How to Check Your Tyre Tread With the 20p Tyre Test
FixMyCar explains how you can check your tyre tread depth using a 20p coin.
Book a car repair nowEllie Dyer-Brown
Wednesday January 24 2024
3 min read
If you’re anything like us, you probably have a handful of loose change lurking somewhere in your car. The good news is that shrapnel like this - specifically 20-pence pieces - can be helpful for checking your tyre tread. This guide explains how.
How to do the 20p tyre test
Place a twenty-pence piece into the main tread grooves of the tyre you want to check. If the outer band is obscured when inserted, the tyre is above the legal limit, and you can continue to use it.
However, if the outer band is visible, this suggests that the depth is insufficient. When you carry out the test, you should check three places on each tyre as they can sometimes wear unevenly. It’s a good idea to do this once every month.
This quick and easy but ingenious hack saves you from purchasing a tread gauge - all you have to do is keep a twenty-pence coin in your car to use repeatedly.
What does the law say about tyre tread depth?
UK law states that the minimum tyre tread depth on cars is 1.6mm across the central three quarters of the tread, around the entire circumference of the tyre.
Why is tyre tread depth important?
The grooves you find on your tyres play an essential role in removing water from the road's surface, allowing for better grip. If your tyres had no treads, you’d struggle to control your car.
The deeper the tread depth, the more effective the tyre at clearing water from the road surface. This results in shorter stopping distances, ultimately making you safer when you get behind the wheel.
There are key differences between the treads on summer and winter tyres - find out more in this guide.
What if my tyres aren't road legal?
In the event that you carry out the 20p test and find that the tread on your tyres is lacking, there’s no need to panic. You can compare car tyre fitting prices from reliable local garages using FixMyCar.
Alternatively, why not try out our network of excellent mobile mechanics who will come straight to you to do the job?
Whichever tyre fitting method you choose, it’s important to replace worn tyres as soon as possible to avoid being caught on the wrong side of the law, or you could end up with a hefty fine of up to £2,500 and three points on your license per tyre.
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Ellie is FixMyCar's Content Manager. She has over three years of experience writing about cars and regularly collaborates with automotive experts to provide trustworthy advice for drivers that is easy understand. Her work has been featured in Yahoo! Finance, iNews, The Daily Express and The Sun. She has a BA in English literature and an MA in creative writing from Durham University. Outside of work, Ellie follows F1 and eagerly awaits Ferrari's next era of dominance in the sport. She drives a Suzuki Swift.